The mechanic's creeper, also known simply as a creeper, is traditionally a low, wheeled platform for supporting a person in a supine position underneath an apparatus, usually an automobile which is supported above a concrete garage floor by a jack or by jack-stands, on which the person is effectuating repair or performing other work. Creepers are virtually indispensable for those who routinely perform such work and do not have a hydraulic or screw-type lift for lifting the apparatus sufficiently high above the floor of the work area to allow the person to stand erect underneath the apparatus.
Creepers are not insignificantly complex. The platform is formed primarily of a rigid planar sheet, typically of wood, which is usually mounted to and supported by a metal frame. Very narrow and low profile wooden side rails are typically attached to the platform to give the user tactile feedback helpful for the user to remain centered on the platform. The frame, or the platform if there is no frame, is supported at four corners by four independently mounted wheels or casters. The wheels or casters are typically formed of metal or hard plastic and have narrow tracks to decrease rolling resistance. Each wheel or caster is supported by a short metal axle that is rotatably mounted to the frame, or to the underside of the platform if there is no frame, so that the axle can be rotated more than 360 degrees about an associated axis that is perpendicular to the plane of the platform.
So that the platform of the creeper can be held close to the floor and to maintain a low profile for the creeper, the wheels or casters are of small diameter, typically about 2-3″. But small diameter wheels/casters are more easily jammed or blocked by small irregularities on the surface of the floor, and so it is a significant limitation of creeper design that the creeper must be used on a floor surface that is hard, smooth, and substantially free of debris to function properly.
Also, to avoid undesirable interference between the user's back, arms or legs and the wheels, the creeper platform is typically at an elevation above the floor that is at least equal to the wheel/caster diameter. Thus it is another significant limitation of creeper design that increasing the diameter of the wheels/casters to reduce the creeper's sensitivity to irregularities in the floor surface necessarily increases the amount of clearance that must be provided underneath the apparatus.
There have been attempts to solve the problem of excess creeper height. That described in U.S. Pat. No. 5,330,209 is representative of the traditional approach. It requires a more elaborate frame and therefore additional cost, and it results in a greater interference with the user's arms.
An alternative approach to solving the height problem known in the art is the “Hover Creeper” which requires a smooth surface and a source of compressed air.
It is both an advantage and a disadvantage that the traditional mechanic's creeper is supported by wheels or casters so that it can be easily moved. For example, a mechanic positioning a creeper in a desired position underneath a vehicle and using a wrench to loosen a bolt exerts a force on the bolt that, if not resisted by the creeper, will cause the creeper to move away from the desired position. The solutions to this problem also typically involve significantly increased cost and weight, in the form of added braking mechanisms that can be set by the user at the desired position. An example is described in U.S. Pat. No. 7,032,909.
The present invention eliminates the aforedescribed limitations of creeper design, and provides for the lowest possible profile along with significant savings in cost and weight.